Net Loss Per Share - Computation of Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net loss	$ (13,075)	$ (5,684)	$ (23,766)	$ (10,373)
Weighted-average common shares outstanding:
Basic and Diluted	27,282,863	22,828,612	27,271,226	22,818,601
Net loss per share, Basic and Diluted	$ (0.48)	$ (0.25)	$ (0.87)	$ (0.45)